We have continued our study of the receptive field of the retinal ganglion cells by analyzing data collected on carp. We have found that the distribution profile of sensitivity across the field under either dark adapted or light adapted conditions can be described as gaussian. The gaussian shape suggests that the dendritic inputs to the ganglion cell would also show a gaussian distribution. Our examination of the morphological evidence indicates that this is not so. In addition, short duration stimuli were found to substantially broaden the quantitatively definable width for this receptive field. Microspectrophotometric absorption curves for the outer segments of carp cones can be grouped into three classes which are identical to those observed in goldfish. Discrepancies which were present concerning the blue cone lambdamax have been resolved. Preliminary efforts to use these "class" curves as templates for the construction of spectral sensitivity curves in other fish such as the cichlids have met with some success.